Title

Author

Degree

Master of Science

Program

Geology

Supervisor(s)

Elizabeth Webb and Brian Branfireun

Abstract

Agricultural systems were investigated in the Motul de San José periphery, an ancient Maya polity in Guatemala, using soil geochemical techniques. The δ13C values of soil organic matter delineated areas of ancient maize agriculture at the satellite center of Kante’t’u’ul. A new method to locate areas of former cacao cultivation or processing was developed using HPLC to detect theobromine, an alkaloid of the cacao plant, preserved in soils. Extraction of spiked soils revealed that theobromine adsorption is inversely correlated with organic matter content of soils. Detection of naturally occurring theobromine was successful, demonstrating its utility as a tracer. Maize cultivation was identified primarily within 50 meters of structures, and theobromine traces were found near water bodies that lacked recent historical evidence of cacao trees. These results suggest the ancient Maya used infield gardens and that former cacao orchards existed in the MSJ periphery providing evidence of diverse Maya agricultural practices.